Japanese Laid-open Patent Publication No. 2005-244104 discloses processes performed in the following order, namely, a covering process for covering the first main surface of a metal plate used as a support substrate for reinforcement in manufacture with a metal thin-film layer having selective etching properties to the metal plate; a lamination process for forming a conductive pattern for forming a metal terminal pad on the first main surface of the metal thin-film layer, and forming a wiring laminated section, by alternately laminating the dielectric layer made of a polymer material and the metal conductive layer, after the covering process; and an etching process for removing the metal plate by selective etching, removing the metal thin-film layer by selective etching, and exposing a conductive pattern 11 formed at the side of the first main surface of the metal thin-film layer, after the lamination process.
Japanese Laid-open Patent Publication No. 2006-059863 discloses a package substrate having no land on the surface layer of a part mounting pad, wherein a circuit surface and an interlayer connection via surface are formed on the same plane as an insulating layer surface in the part mounting pad. Its manufacturing method includes a process where a nickel plating is used as a supporting body and an insulating layer and an interlayer connection via are formed thereon, and a process where the nickel supporting body is peeled off to form the part mounting pad having the interlayer connection via as the surface layer.
According to these methods, a pitch of electrode pads may not be further narrowed.